The purpose of these studies is to investigate the effect of u-PA on the antitumor efficacy of BCG therapy for superficial bladder cancer, to investigate the potential role of monitoring u-PA levels as a predictor of response to BCG therapy, and to investigate methods of enhancing BCG therapy through modulation of u-PA activity. Initial studies will assess the effect of a standard preparation of u-PA on the BCG-FN interaction and antitumor efficacy in vitro and in a murine bladder tumor model. Further studies will correlate naturally occurring u-PA activity, receptor levels and secretion in normal and malignant urothelium with BCG-FN attachment and antitumor efficacy in tissue culture and a murine bladder tumor model. Finally, an enhanced antitumor effect will be sought with the use of u-PA inhibitors in conjunction with intravesical BCG therapy.